Why a ground operation is not enough to reopen the Strait of Hormuz

If it proves impossible to reopen the Strait of Hormuz from the sea, the temptation is to try from land, and in American planning centres this scenario is being discussed with increasing urgency. It is probably the most deceptive of the options on the table. Before the war, around twenty million barrels a day passed through the Strait, accounting for twenty-seven per cent of global seaborne crude oil trade. Today that flow has been reduced to a fraction of that, and Brent crude has surpassed one hundred dollars a barrel. The question has become unavoidable: can the Strait of Hormuz be reopened with a ground force? Tactically, the answer is yes. Strategically, it is no. It is precisely this discrepancy that makes the scenario dangerous. The idea seems intuitive: occupy a few islands, reopen the waterway. The problem is that the Strait of Hormuz does not work like that. At its narrowest point, the Strait is thirty-four kilometres wide, with two shipping lanes of around three kilometres each, and Iran controls it through a combination of coastal missiles, attack drones, naval mines and swarms of fast craft from the IRGC-N (the naval branch of the Islamic Revolutionary Guard Corps), which goes far beyond a mere presence on the islands. Operation Epic Fury sank over fifty conventional Iranian naval vessels, but more than sixty per cent of the IRGC-N’s fleet of small craft was still operational after six weeks of war. It is these small craft, and not the frigates that ended up at the bottom of the Gulf, that form the heart of the area’s denial system.

The islands at the centre of the debate – Abu Musa and Larak at the entrance to the Strait, and Kharg in the northern Gulf, 660 kilometres away – each have a different strategic rationale. The first two would serve to disrupt operational control of the corridor. Kharg, through which ninety per cent of Iran’s oil exports pass, forms part of a distinct strategy aimed at striking at the regime’s economic leverage rather than reopening the passage. Neither option works on its own, and the reasons are structural. The first limitation is geographical. Capturing Larak without capturing Qeshm is pointless, because Qeshm houses a significant proportion of the IRGC’s anti-ship missiles in its underground tunnels. Neutralising both without touching the mainland coast solves nothing, because that coast stretches for over two thousand kilometres, and from any point along it Iran can launch missiles, drones and mobile batteries that do not require fixed bases. The Shahed-136 drone has a range of over a thousand kilometres and requires nothing more than a lorry as a launch platform, which renders any island conquest irrelevant in the face of the overall threat.

The least intuitive limitation concerns perception. To halt commercial traffic through a strait, it is not necessary for missiles to strike: it is sufficient for shipowners and insurance companies to believe that the risk exists. Insurance premiums for transit through the Gulf had already risen before the fighting began, based solely on the threats. Even if Iran’s coastline is only partially degraded by air strikes, this widespread deterrent capability remains intact, because trade grinds to a halt out of fear, not just because of explosions. There is also an even more difficult problem to solve. Iran has deployed its missile capabilities inland, partly in the Zagros mountain range, knowing full well that any US air campaign would attempt to neutralise them. Visible coastal systems were degraded by Operation Epic Fury, but those scattered inland – mobile and designed to survive bombardment – remain largely operational. Any ground force on the islands would find itself exposed to fire from positions that no island garrison can reach and no aircraft can permanently neutralise.

The planners’ response is a low-altitude air assault carried out using MV-22 Ospreys – military tiltrotors capable of hovering – supplemented by airborne units and special forces, as a traditional amphibious assault is too vulnerable to anti-ship missiles along the approach corridors. However, this operational margin is also threatened by Russian-made man-portable air defence systems that Iran has begun to acquire, designed specifically to target this type of aircraft. Once on the ground, the problem shifts from conquest to holding the position. American amphibious contingents are self-sufficient for fifteen days, after which they require resupply under fire. Iran would not need to recapture the islands immediately: it would suffice for it to turn them into costly and politically embarrassing outposts through persistent attrition, until holding the position became the true American mission. What began as a campaign to protect freedom of navigation would turn into an indefinite territorial commitment, in a theatre where US stocks of precision munitions and missile interceptors have already been under structural strain for months.

The domestic political landscape in the US is the variable that no military analysis can ignore. Trump cannot afford unsustainable energy prices with the mid-term elections in November, but nor can he afford military casualties that would remind the public of the Iraq War. Iran is aware of this asymmetry and regards it as the real battlefield: it is not necessary to win on the ground; it is enough to make the cost high enough for long enough until Washington decides that the stakes are not worth the price.

There remains one argument that supporters of the ground operation option do not always state explicitly, but which underlies their entire line of reasoning. Perhaps the regime will collapse following the first direct attacks on Iranian soil; perhaps simply deploying the Marines will be enough to bring down a leadership that has already been decapitated and deprived of a large part of its military top brass. In theory, it is not impossible, but this gamble has already been taken and has already failed: rapid collapse was the implicit premise of ‘Epic Fury’ from day one, with the elimination of the Supreme Leader and strikes against the top echelons of the Revolutionary Guards. The regime has not fallen. It has closed the Strait, struck American bases in the Gulf, and withstood weeks of bombing unprecedented in the recent history of aerial conflict in the Middle East. Building a new initiative on this very same premise – one far more complex and costly in terms of human lives – amounts to doubling down on a losing hand, betting that the enemy will give in this time, even though it has already shown it will not do so under the worst conditions it has ever faced.

The logic behind the ground operation assumes that there is a physical point whose capture would amount to control of the Strait, whilst the Strait is held by a dispersed, mobile and redundant network stretching across thousands of kilometres of coastline and hinterland. Capturing an island within that system amounts to plugging a hole in the net. The threat simply shifts to all the others.